Extension-ladder



(No Model.)

0. W. HOWARD. EXTENSION LADDER.

Patented do. 25, 1894.

Wines 5 e v 14. /M

UNITED STATES PATENT OFFICE.

' CHARLES W. HOWARD, OF NORTH HECTOR, NEW YORK.

EXTENSION-LADDER.

QPEGIFICATION forming part of Letters Patent No. 531,534, dated December25,1894.

I Application filed April 13, 1894. Serial N- 507,455- (No model.) I.

To wZZ whom it may concern:

Beit known that I, CHARLES W. HOWARD, a citizenof the United States,residing at North Hector, in the county of Schuyler and State of NewYork, haveinvented certain'new and useful Improvements inExtension-Ladders; and I-do declare the following to be a full, clear,and exact description of the invention', such as will enable othersskilled in the art to whichit appertains to make and .usethe same,reference being bad to the accompanying drawings, and to the letters ofreference marked thereon, which form a part of this specification.

The invention relates to extension-ladders whose sections are held adjustably to one another so as to make different lengths of ladder, as maybe required.

The invention consists in the particular means employed to lock thesections together.

Figure 1 of the drawings is a vertical section, showing an extensionladder in two sections with my lock mechanism Fig. 2, a detailperspective view of the detent; Fig. 3, a detail view of the lever whichdepresses the detent; Fig. 4:, a vertical section of a modification fordepressing the detent.

- movable one.

In the drawings A and 13 represent two ladder-sectionsof which theformer is the base or stationary section while the latter is the On theupperends of section A are guides at a and a subjacent support a for themovable section B.

C is an elbow-lever fulcru med near the vertex of its angle to a rung D,and E a detent fast on the rung D, the latter being journaled in theladder sides A A.

The detent E has two parallel arms 0 0 concaved in front to fit 0n therung and connected subjacently, near each end, by a crossbar.

To the lower crossbar, is fastened one end of a spring F coiled about ajournaled rung D and fastened'thereto at the other end.

On the outer end of each arm of the detent is formed a rabbet in whichplays the arm 0 of the lever when it depresses the detent, so as to .leta rung of the movable section pass over it and then rise up behind it.

The movable section B may be started upward on the section A andsuccessive rungs permittedto pass over the detent until the desiredlength of ladder is obtained, when a rung is allowed to'press againstthe detent.

,The section may be also entered into the in the drawings, it is properto add that the detent may be made shorter and pivoted to the sides ofthe ladder by inserting an extra rung or other fulcrum, without changingits character or function.

The stops or detents; and cams or levers,

may be fixed on the rungs, the latter being movable, or they may beloose upon the rungs, the latter being the journalsupon which the formerare fulcrumed.

I am aware that hooks on one section to engage rungs on the other havebeen employed on extension ladders, a clearer being pivoted to the hookand the hook being adjustably held by a setscrew; but

What I claim as new, and desire to protect by Letters Patent, is-

In extension ladders, two elbow-levers made fast near the elbow to aspring-actuated turn shaft or rung, near the upper end of the stationary section, and a two-armed detent on a spring-actuated turn-shaftof said section; whereby the rungs on the sliding section depress thelevers andthe levers depress the detent, while the springs retractdetent and levers as shown and described.

In testimony whereof I affix my'signature in presence of twowitnesses. 1

' CHARLES W. HOWARD. Witnesses:

W. H. OLIN,. B. P. OLIN;

